1. Field of the Invention
The present invention relates to an elastomeric seal for sealing a pipe relative to a cylindrical inner surface of a housing in a plug-in coupling. More specifically, the present invention relates to a seal for sealing a pipe that is held in a push-in part of a plug-in coupling relative to the cylindrical inner surface of the housing of the plug-in coupling.
2. Description of the Related Art
A prior art elastic seal for a hydraulic plug-in connection is disclosed in German reference DE 197 14 801 C1. This prior art seal includes a shaped profile on an interior circumferential surface which engages a shaped profile formed on the exterior circumferential surface of the sleeve with a positive fitting to secure the sealing member to the sleeve. At least one exterior sealing lip is formed on the exterior circumferential surface axially in the region of the shaped profile. In the assembled state of the plug-in connection, the exterior sealing lip is in contact with an interior circumferential surface of the coupling with elastic deformation. In this manner, this reference claims that better handling of the plug-type fitting during assembly of the plug-in connection and a better sealing action of the sealing member in the operation of the plug-in connection are ensured.
It is obvious that the elastic sealing member with the shaped profile of the sleeve can be easily assembled, since the shaped profile of the sealing member can be snapped in merely by stretching open. However, it becomes apparent on dismantling that the union of the sealing member with the sleeve need not necessarily remain in their original jointed state. When the plug-in union is released the end half of the sealing member remains in the sleeve under prestress while the joint union has already been released from the prestress exerted by the cylindrical interior surface of the outer housing. In this case, the sealing member may become released from the sleeve and remain within the internal diameter of the housing while the sleeve with the pipe to be sealed are pulled out of the housing. When reassembly is attempted, the joint union is no longer adequately produced and a sealed connection is no longer guaranteed.
It is an object of the present invention to provide a joint connection between an elastomeric seal and a push-in part of a plug-in coupling which can no longer release itself even in the event of frequent actuation of the plug-in connection.
In contrast to the above described prior art device, an elastomeric seal according to the present invention for sealing the pipe in a push-in part of a plug-in coupling relative to a cylindrical interior surface of a housing of that plug-in coupling is sealed by a positive-fitting joint connection that connects the elastomeric seal to the push-in part. An annular molding on the elastomeric seal is no longer drawn from the outside via a collar but snap-fitted from inside into an annular groove. As a result of the insertion of a pipe in the push-in part, the joint connection between the elastomeric seal and the push-in part is locked in that the annular molding of the elastomeric seal can no longer be pulled out from its annular groove because the exterior surface of the pipe prevents the radial inward movement of the annular molding. Accordingly, frequent actuation of the plug-in connection does not cause the elastomeric seal to be released from the push-in part. To improve this connection, the planning of the diameter relationships on a web-shaped connection in the annular molding and on the internal diameter of the collar interacting with the web-shaped connection may be sized to achieve a compression of the web-shaped connection whereby the above-mentioned locking is further improved.
According to an embodiment of the present invention there is described a push-in part and an elastomeric seal for use with a plug-in coupling including a housing having a cylindrical interior surface, the push-in part and the elastomeric seal being insertable with a pipe into the cylindrical interior surface for sealing a cylindrical and uninterrupted exterior surface of the pipe relative to the cylindrical interior surface of the housing. A radially outward-facing annular lip arranged on said seal is insertable in the cylindrical interior surface of the housing. A radially inward-facing annular lip arranged on said seal is insertable over the exterior surface of the pipe. The radially outward-facing annular lip is contactable with the cylindrical interior surface in a prestressed state and the radially inward-facing annular lip is contactable with the exterior of the pipe in a prestressed state when the push-in part is inserted with the pipe into the cylindrical interior surface. A positive fitting joint connection is arranged between the seal and the push-in part for connecting the seal to the push-in part. The positive fitting joint connection is non-releasable when the pipe is inserted through said radially inward-facing lip of said seal.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.